Astronomers have captured unprecedented data from the Sun's magnetic field, which could help explain why the outermost layer of the Sun is hundreds of times hotter than the surface.

Highlights:

• New data from the Daniel K. Inouye Solar Telescope (DKIST) in Hawaii reveals a serpentine topology of the magnetic field in the lower solar atmosphere.
• This could help explain why the outermost layer of the Sun (corona) is hundreds of times hotter than the surface (photosphere).
• The research was published in Astrophysical Journal Letters and was supported by research funding from the Science and Technology Facilities Council, which is part of UKRI, Horizon 2020, and the National Science Foundation, USA.

Details:

The DKIST is the most powerful solar optical telescope on Earth and enables record-breaking observations of the Sun. The project led by Queen's University Belfast in collaboration with the University of Sheffield, the NSF's National Solar Observatory, the High Altitude Observatory at California State University, the Max Planck Institute for Solar System Research in Germany, and Eötvös Loránd University in Hungary, harnessed this power to reveal a new, complex, snake-like pattern of energy in the magnetic field.

In the past, much research into the heat variations between the corona and photosphere has focused on "sunspots" - very large, highly magnetic, and active regions - that can act as conduits for energy between the Sun's outer layers. Away from sunspots, the so-called "quiet sun" is covered in convective cells known as 'granules', typically about the size of France, that harbor much weaker, but more dynamic magnetic fields that may hold the secrets to balancing the energy budget of the chromosphere.

Most observational reports of the past decade have found that magnetic fields are organized in terms of small loops in the quiet photosphere. With DKIST, researchers have detected something unexpected, finding the first evidence for a more complicated pattern consistent with a snake-like variation in the magnetic orientation.

Professor Michail Mathioudakis, co-investigator on the research and Director of the Advanced Research and Engineering Centre (ARC) at Queen's said: "The more complex the small-scale variations in magnetic-field direction, the more plausible it is that energy is being released through a process we call magnetic reconnection - when two magnetic fields pointing in opposite directions interact and release energy that contributes to atmospheric heating.

"We have used the most powerful solar optical telescope in the world to reveal the most complex magnetic-field orientations ever seen at the smallest scales. This brings us closer to understanding one of the biggest conundrums in solar research.

Professor Erdelyi added: "Thanks to this research we may be one step closer to comprehending the Sun, our life-giving star".

"These are fantastic results achieved by a combination of junior and senior scientists across a wide range of institutions on both sides of the Atlantic Ocean. The DKIST solar telescope, the largest of its kind, has opened revolutionary new avenues in solar physics," Erdelyi said.